For an outside observer, what you're saying in a nutshell is

I don't think that's what wuf is saying, that's simply how you've interpreted it.

There's two points to what wuf is saying.
BLM are saying "we don't give a toss about whites, this is only about us",
and lots of regular white people, not necessarily wuf, are perhaps responding "yeah I hear ya, but I ain't doing shit unless it helps me".

If the message was "fuck the system" then it would be much more powerful because it would be much less divisive. It's the system that's racist, right? Overthrow it. You're not going to do that if you exclude the largest demographic in the country.